Rotary gas-engine.



F. D. THOMAS.

ROTARY GAS ENGINE. 1121110111011 rum) MAY 1, 1909.

987,929; Patented Mal-.28, 1911.

3 SHEETS-SHEET 1.

WITNESSES: INVENTOR m walla 4M2) mm ATTORNEY P. D.. THOMAS.

ROTARY GAS ENGINE.

APPLICATION IILED MAY 1, 1909.

Patented Mar. 28, 1911.

3' SHEETS-SHEET 2.

INVENTOR WITNESSES $7 Wam- ATTORNEY P. D. THOMAS. ROTARY GAS ENGINE.

APPLICATION FILED n 1, 1909.

987,929. Patented ar. 28, 1911.

3 SHEETS-SHEET 3.

WITNESSES: 1 VENTOR BY a. I

ATTORNEY FRANKLIN I). THOMAS, 0F SAGINAW, MICHIGAN.

ROTARY GAS-ENGINE.

Specification of Letters Patent.

Patented Mar. 28, 1911.

. Application filed May 1, 1909. Serial No. 493,431.

To all whom. it may concern:

Be it known that I, FRANKLIN D. THOMAS, a citizen of the United States, residing at Saginaw, in the county ofuSaginaw and State of Michigan, have invented certain new and useful Improvements in Rotary Gas-Engines; and I do hereby declare the following to be a full, clear, and eXact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to rotary engines.

The style of engine herein described and illustrated is the internal combustion type but it is obvious that it might be operated by compressed air or steam.

The objects are to provide a perfectly balanced and noiseless engine which is economical in operation and which will develop a greater amount of power than can be ob tained by any other engine having the same piston area.

Another object is the provision of a reversible. engine.

A further object is the provision of .an engine which can be easily and quickly as sembled and disassembled, of simple and compact form with no expensive parts or complicated features and practically valveless.

l-i still further object is the provision of an engine which shall utilize the maximum expansion of the motive fluid.

Still another object is the provision of an engine in which there is no back pressure, and a minimum of friction and lostpower.

Another object is the provision of an en gine having a novel system of lubrication and'one in which there is a perfect combustion and no back firing.

To these and other ends, therefore, my invention consists in certain other novel fea- A tures and combinations such as will be more fully described hereinafter and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a vertical sectional view partly in full lines through a machine embodying my invention, Fig.2 is a eross-sectional view on line 127-410 of Fig. 1, Fig. 3 is a detail top plan view of the working parts removed from the cylinder, Fig. 4 is'a View in side elevation, Fig.5 is a detail View showing the yoke which controls the locking and unlocking of the drums and their respective sections, and Fig. 6 is a detail View of such yoke viewed from the edge.

As shown, the invention consists of a rotary internal combustion engine embodying novel means whereby the direction of rotation .of the pistons of which can be easil and quickly reversed.

A indicates a water jacketed circular cylinder formed preferably in halves and provided with the flanges 1, secured together by means of the cap screws 2. The opposite side faces of the cylinder are provided with the openings 3,3 and carry the semi-circular flanged casings 28. The cylinder chamber is preferably circular and contains the pistons which are exact duplicates so that a description of one will suflice for both. Each piston 4 and 5 consists of a centrally apcrtured annularly flanged disk, the disks arranged so as to form an internal chamber 6, the free edges ofv the flanges abutting to form a sliding joint. The flangeof each disk is equipped with a pair of diametrically opposed wings 7, 8, 9 and 10, projecting from the periphery thereof, the wings extending across the cylinder from side to side. The wings on one flange project over the periphery of the flange of the opposed piston, and each wing is grooved along its opposite ends to receive packing rings 11,

which engage the opposite heads of the cylinder. Those portions of the under surfaces of the wings which overlie and rotate relative to the opposed pistons are grooved as indicated at 12, to receive packing and the outer edges of the wings are similarly grooved to receive packing 13 which engages the inner periphery of the cylinder.

Located at some convenient point in the periphery of the cylinder are the interchangeable inlet and exhaust ports 14 and 15, spaced apart from each other asshown, and preferably diametrically opposite thereto are the ports 16, 16, which receive the spark plugs 17, 17, such ports likewise spaced apart from each other. A casting 18 is secured to the cylinder, the casting provided with passages registeringand forming continuations of the interchangeable inlet and exhaust ports, such passages leading to a the latter being combined and registering valve seat in which is received the hollow reversing plug valve 19. This valve is provided with a peripheral groove 20 extending semi-circumferentially thereof and adapted to connect one or the other of the ports 14 or 15 with-a chamber 21 in the casting with which one or more carbureters (not shown) may communicate. The hollow interior of the plug valve communicates by means of a lateral opening 22 with them:- haust port, the hollow interior discharging into an outlet 23 in the casing. The respective spark plugs 17, 17 are connected to a high tension switch 24 of any usual construction, operated by a shaft 23, for cutting the current over from one spark plug to the other in reversing the engine, 26 indicating the binding posts for the battery connections.

Projecting laterally from the pistons 4 and 5, through the openings 3 of the cylinder, are the hollow drums 27, 27' arranged concentrically relative to the shaft apertures of the pistons, and themselves provided with apertures registering with those in the piston disks. These drums are inclosed in the semi-circular flanged casing 28, bolted to the respective side faces of the cylinder, as at 29. The casings are provided with journals 30, 30, which may conveniently cont prise the thimbles 31 encircling the bushings 32.

lVithin the internal chamber 6 is located the means for transmitting the rotary movement of the pistons to the shaft, such means consisting of a diiferential gearing. The gears 33 and 34 are secured to the inner faces of the respective piston disks, the gears provided with oppositely extending sleeves 51 passing through the centrally disposed apertures in the pistons and drums and through the bushings 32 of the journals. A. shaft 35 is loosely received in the sleeves, and a carrier-36 is keyed to that portion of the shaft within the internal chamber 6 and between the gears and 3-1, such carrier having the diametrically projecting pintles 37 thereon, on which are journaled the pinions 38 meshing with-the gears 33 and ltt will thus be seen that the rotation of the pistons will re' tate the gears 33 and, 34 carried thereby, such rotation being transmitted to the shaft 35 through the pinions and carrier. Tt is necessary. however, in operating this coustruction as a rotary internal combustion em gine, that means be provided to automatically lock the piston alternately in order that the wings of the locked pistons may serve as stationary ,abutmeuts, and to this end i proide the drums 27,27 in the casings 2d. tirdoves 39 are arranged peripherally of the drums, such grooves each being offset-laterally at two diametrically opposite points. The offsets consist of the steps 40 and 'stl,

l l l i with pockets 42 formed in the inner walls of the groove, the outer walls of the grooves be ing provided with double cams whosefaces 43 lie opposite the steps 40, the peaks 44 of the cams lying opposite the steps 41. These ofi'sets lie in alinement with the wings of the respective pistons and rotate therewith.

U-shaped yokes 45, 45 carry the offset trunnions 46 which are journaled in the flanges 47 of the casings, the yokes partially encircling the drums. One trunnion on each yoke is extended beyond the flanges of the casing and carries a crank 48, the cranks being connected by a rod 49' so that movement of one'yoke is communicated to the opposite yoke. Each yoke carries a roll 50, 50 received in the groove 39. The lodgment of the roll in either of the pockets 42 of its groove operates to lock the drum and piston against rotation and simultaneously releases the opposite drum and piston to permit the rotation of the latter.

The operation of my invention is as fol-' lows: The piston 4 carrying the wings 7 and 8 is held in locked position by the roll 50 which lies in the step 41 and pocket 42 of the drum 271. The reversing and combined inlet and exhaust valve 19 is in the position shown in Fig. 2, wherein 14 is the inlet port and 15 the exhaust port. The wings 9 and '10 of the piston 5 being in the positions shown in Fig. 2, a combustible charge is under compression between the fixed wing 7 and the movable wing 9. The charge being ignited from the spark plug 17, the expan-' sion drives the wings 9 and 10 and their piston 5 throughout a half revolution in the direction of the arrow, such movement of the piston 5 rotating the gear 34 throughout one-half a revolution and the latter rotating the pinions and hence, the shaft 35 to which they are secured through a quarter of a revolution. From this it will be seen that I double the force communicated to the shaft through halt arotation of the piston. Hence, a full rotation of the piston will quadruple the force imparted to the shaft.

The movement of the wing 9 in the direct-ion I of the arrow operates to scavenge the annular piston chamber,- driving the products of combustion of the charge last exploded, out of the chamber into the exhaust port 15 and thence through the opening 22 into the hollow plug and the exhaust opening 23.

Meanwhile, the wing 10 moves upward in the direction of the arrow and operates to draw in a charge behind it through inlet port 14, groove 20 and chamber 21. It also compresses 'between itself and the locked wing 7, the charge previously drawn into the piston chamber by the upward movement of the wing i. The rotation of the piston 5 has rotated its drum 27, the groove at which moves relative to the roll 50 on the yoke 45. As the wings 9 and 10 approach the stationary wings 8 and 7 respectively, the offset portion of the groove 39 nears the roll 50. Now, at about the time the wing 9 reaches the exhaust port 15, the roll 50 slips into the adjacent step 40 of the offset, being forced the'reintoby the face 43 of the opp0sed cam. This movement of the roll 50 swings the yoke 4.5 sidewise and through the link 49, such movement is communicated to the yoke 45 and roll 50. Owing to the cranked connection of the yoke with its trunnions, such movementwill throw the roll 50 out of its pocket 42, thereby unlocking the piston 4, and the inertia of the moving parts of the mechanism will cause piston & to rotate until the roll 50 lies in the step 0 of its groove and thence out into the annular portion of such groove. The .movement of the piston e from locked to partially unlocked position permits the movement of the pistons 7 and 8 to the positions occupied by the pistons 9 and 10 in Fig. 2, and as the roll '50 moves out into the annular portion of its groove, the continued movement of piston 5 causes the peak 44 of 'the cam to'guide the roll 50 into the step 41 and pocket. l2, thereby locking the piston with its wings 9 and 10 in the positions occupied by the wings 7 and 8 in Fig. 2, whereupon the foregoing operation is repeated. The provision of the pockets 42 for the rolls 50, 50, while not absolutely essential, .constitutes a means for relieving the wall of the groove from wear and reduces the strain on the locking yokes. The sleeves 51 of the gears 33 and 34: extend past the journals 30 of the casings 28, their projecting ends being equipped with spark timers 52 of any convenient construction, thecontact disks 53 of which cotiperate with the contacts 54 being actuated by arms 55 connected by links 56 and cranks 57 to a shaft 58 controlled by a lever 59. By means of this construction, the ignition of,the charge may be timed to take place at any point in the stroke or travel of the wings.

The engine is easily reversed and as one means for accomplishing this end, I providethe stem 60 of the valve 19 with a gear 61 in mesh with a second gear 62 actuated from the shaft 25 which also controls the high tension switch 24:, the shaft being operated by a hand lever 63. Assuming the parts to be in the position shown in Fig. 2, with the charge between wings 7 and 9 about to be ignited. By a movement of the shaft 25, the gears 61 and 62 are operated to partially rotate the valve 19 so that its groove 20 will connect port 15 with the chamber .21, and the exhaust o ening 22 will register with port- 14. Simu taneously therewith, the electric current will be switched to deenergize spark plug 17 and energize spark plug 17'. The inertia of the engine, together with the &

force exerted by the compressed charge against the wing 9, will cause the rotation of piston 5 in-thedirection of the arrow, and the compression of the charge between pistons l0 and T. the wing T, the compressed charge between those wings is ignited and the shaft rotated in the reverse direction. If the charge between pistons T and 9 is ignited, prior to the reversal of the valve, the piston i will be released and piston 5 locked, the inertia of the parts then causing wing 8 to move toward wing 10, which at that time will occupy the position of wing T in Fig. 2 and the same result take place. There are two charges in the piston chamber at all times, cne being compressed and the other under compression.

The lubrication of my engine is accomplished by introducing a quantity of oil into the hollow drums which serve as reservoirs, the oil being splashed onto the sleeves 51 and through the centrally-disposed openings in the drum and in the piston disks. whence itis distributed to the gears and bearings. Other means of lubrication can be utilized. however, without departing from the spirit and scope of my invention, one aspect of which consists in the combination with the rotating pistons, of a gear mechanism arranged as shown and actuated by the pistons. -Another feature of my invention consists in the provision of automatic locking means of the type shown, for alternately locking one piston against rotation and releasing the opposite piston. By the use of the fourpistons shown. four charges are. successively drawn into the annular piston chamber. four compressions take place and an equal number of explosions for each complete rotation of the shaft 35, the pistons making two complete rotations for every single rotation of the shaft. Another ad vantage gained by my construction is that the upper half of the casing 28 and cylinder A can be removed. thereby disclosing the entire working parts of the engine, by merely taking ofi' thercap screws 2. X0 tools aside from a wrench are needed to take the engine apart or assemble the same. the drums and pistons with their gears sliding ott the shaft. leaving the latter bare with the exception of the carrier.

My invention consists of but few parts which are not liable to get out of order easily. and it is readily assembled by an un skilled laborer. It is light in weight, compact and small. It will be seen that each wing sustains the concussion of the explosion but once in four times, hence. the life of the engine is prolonged. Furthermore, no back firing is possible. owing to the close fit of the wings against the walls of the annular piston chamber. assisted by the packing rings. Also, there is but a minimum of As the wing 10 approaches back pressure caused by the compression of the succeeding charge between the upper stationary wing and the succeeding movable wing, and this is the only back pressure which is brought to bear on the shaft. Again, there is but a single valve used in the entire construction and no springs whatever are employed. The valve, except when it is desired to reverse the direction of motion of the shaft, remains stationary and does not operate as a puppet. It will be seen that each wing corresponds to the piston area of an ordinary reciprocating piston engine and that the distance between the spark plug 17 and the exhaust port 15 corresponds to the piston travel of such reciprocating piston engine. However, the length of travel'of the wings of my engine is greatly in excess of the length of stroke of the ordinary reciprocating engine, so thatI am able to utilize practically all of the pressure generated by the ignition of a charge, whereas in the ordinary reciprocating style of gas engine, fully 40% of the pressure is wasted through the exhaust. By utilizing the pressure generated, I do not require a mufl'ler on my exhaust, as there will be no noise incident to the discharge of the exhaust. In other words, I provide an engine having a comparatively slow but powerful shaft speed, Whereas the reciprocating engines sacrifice powerfor speed. I

The ordinary reciprocating engine requires a crank shaft and if more than one engine is used, an expensive crank shaft is necessary in order that the engines may be evenly balanced. My engine is self balanced and requires merely. the ordinary straight shaft, as many engines being coupled on the same shaft as are desired. There is no vibration, since the wings travel in a circular path, and no lost..power in passing over dead centers. Since the charge is drawn into the cylinder directly from the carbureter and is not forced in by compression, a less'amount of fuel is necessary in operating my engine than is required by en- .gines of the reciprocating type.

Having thus fully disclosed my invention, What I claim as new, is

1. A rotary engine comprising a cylinder, pistons in the cylinder, wings on theopistons, means for introducing motive fluid between the pistons, a shaft passing loosely through the pistons, gears carried by the pistons, and gears secured on the shaft and meshing with the gears on the pistons.

2. A rotary engine comprising a cylinder, pistons in the cylinder, wings on the pistons, means for permitting successive pistons to draw motive fluid into the cylinder between the piston wings, the motive fluid being compressed by the movement of one piston wing toward the next wing in advance thereof. means for automaticallv locking one meshing with the gears on the pistons.

of the pistons and simultaneously releasing the other piston, a shaft passing loosely through the pistons; gears carried by the pistons, and gears secured on the shaft and 3. A rotary engine comprising a cylinder having a plurality of ports, a reversible valve having an intake port leading from a source of power and an exhaust opening,

means for operating the valve so that the respective intake port and exhaust opening thereof may register with either one of the cylinder ports, pistons received in the cylinder and movable independently of. each other, a transmission gearing inclosed by the pistons, and a shaft actuated by the operation of the gearing.

4. A rotary engine comprising a cylinder, a shaft passing therethrough, circular hollow pistons received in the cylinder and movable relative to each other, wings carried by the respective pistons, gears mounted within and fast on the respective pistons, a carrier on the shaft intermediate the piston gears, and pinions journaled on the carrier and meshing with both piston gears simultaneously.

A rotary engine comprising a cylinder, a shaft passing through the cylinder, pistons in the cylinder, the pistons rotating independently of the shaft and of each other, wings on the pistons, means for automatically locking one piston and releasing the remaining piston alternately, and transmission gearing carried by the pistons and shaft respectively for increasing the force transmitted from the pistons to the shaft.

(3. A rotary engine comprising a cylinder, a shaft. passing therethrough, circular flanged pistons received in the cylinder, wings carried by the pistons, the flanges of the pistons engaging throughout their circle, to form a sliding joint, the pistons provided with apertures to receive the shaft, gears secured to the inner faces of pistons, means carried by the shaft and meshing with the gears for transmitting motion to the shaft, sleeves projecting from the gears, the sleeves loosely encircling the shaft, means for introducing successive charges to the cylinder between the wingsof the respective pistons, means for exploding the charges, and spark timers on the sleeves of the gears for controlling the time of ignition of the charges.

7 A rotary engine comprising a cylinder consisting of upper and lower sections, means for removably connecting the sections, pistons in the cylinder, wings on the pistons, a shaft passing throughthe cylinder and pistons, and a differential gear, the elements of which are carried by the pistons and shaft respectively, to transmit the mo tion of the pistons to the shaft.

8. A rotary engine comprising a cylinder,

pistons in the cylinder, wings on the pistons, a shaft passing through the cylinder and pistons, a difi erential gear, the elements of which are carried by the pistons and shaft respectively, to transmit the motion of the pistons to the shaft, and means for locking and releasing the pistons alternately.

9. A rotary engine comprising a cylinder,

pistons in the cylinder, wings on the pistons, a shaft passing through the cylinder and pistons, drums carried by the respective pistons, the drums equipped with cam grooves having locking steps, rolls in the grooves, yokes carrying the rolls, means connecting the yokes, and means for transmitting the motion of the pistons to the shaft- 10. A rotary engine comprising a cylinder, pistons in the cylinder, a shaft, means for transmitting the motion of the pistons to the shaft, drums carried by the pistons and having grooves therein, a portion of the grooves being stepped, and a stepped cam located opposite the stepped portion of the groove, rolls received in the grooves, swing ing means on which the rolls are received, and a rod connecting the swinging means.

11. A rotary engine comprising a cylinder, pistons therein, a shaft, means for transmitting motion from the pistons to the shaft, drums carried by'the respective pistons. the drums having cam grooves formed therein, locking means associated with each cam groove. and a rod connecting the loclting means to cause the release, of one drum when the other drum is locked.

12. A rotary engine comprising a cylinder, pistons therein, a shaft,1neans for trans mitting motion from the pistons to the shaft, and means for locking the pistons alternately againstmovement, such means com prising grooved drums secured to the pistons and projecting laterally through the sides of the cylinder, casings inclosing the drums, yokes havingmrunnions journaled in the casing, rolls on the yolres received in the cam grooves, and means connecting the yokes.

18. A rotary engine comprising a cylinder, pistons therein, a shaft, means for transmitting motion from the pistons to the shaft, means for alternately locking the pistons against moven'ient, such means comprising drums secured to the pistons and provided with grooves, the inner walls of the grooves being stepped, stepped cams on the outer walls of the grooves opposite the stepped portions of the grooves and cooperating therewith, and connected loclring members cooperating with the grooves.

14. A rotary engine comprising a cylinder, pistons therein, a shaft, means for transmitting motion from the pistons to the shaft, means for alternately locking the pistons against movement, such means comprising drums secured to the pistons and provided with otlset grooves having po kets formed in the offsets, and interconnected locking members projecting into the grooves and alternately receivable in the otfset pockets.

15. A rotary engine comprising a cylinderhaving inlet andexhaust ports, a chambered valve casing having ports registering with the cylinder ports, a hollow valve in the casing, the valve having an opening connecting one of thecylinder ports with the hollow interior of the valve and also pro and exhaust ports, a reversible valve for connecting the cylinder ports with the intake and exhaust ports, pistons in the cylinder, wings on the pistons, a shaft, means for communicating the motion of the pistons to the shaft, spark lugs for exploding the charge on either side of a wing, a switch for energizing one or the other of the spark plugs, and means for simultaneously reversing the switch and valve.

17. A reversible rotary engine comprising a cylinder, pistons in the cylinder, wings on the pistons, a shaft arranged concentrically with and passing loosely through the pistons, gears carried by the shaft, other gears carried by the pistons and in constant mesh with the gears on the shaft for transmitting motion from the pistons to the shaft, means for alternately locking the pistons against.

movement, and means for permitting one piston to have a slight preliminary forward movement prior to its complete release as the next adjacent piston approaches-its locking position.

18. A rotary engine comprising a stationary cylinder, pistons in the cylinder, wings on the pistons to turn the latter in the cylinder, means for introducing motive fluid between the wings, a drive shaft passing loosely through the pistons and the cylinder ends, means for transmitting motion from the pistons to the shaft. and means, other than the powertransmission means and connected to be controlled by the rotation of the pistons. for automatically and temporarily locking successive pistons against movement in either direction, and releasing the remaining piston for movement,

19. A rotary engine comprising a cylinder, pistons in the cylinder, wings on the pistons, a shaft, means for transmitting motion from the pistons to the shaft, drums on the pistons, the drums having cam grooves, locking members received 'in the grooves, yokes carrying the looking members, suitably journaled trunnions offset from the yokes, and means for connecting trunnions on the respective yokes.

20. A rotary engine comprising a cylin der having openings in its sides, flanged pistons in the cylinder, the free edges of the flanges engaging to form a sliding joint, wings on the pistons, a shaft passing through the pistons, gearing inclosed within the pistons for transmitting motion from the pistons to the shaft, hollow grooved drums.

carried by the istons and projectin through the openings 1n the cylinder, an locking means cooperating with the grooved drums to automatically lock the respective pistons alternately against movement, the hollow drums adapted to contain lubricant.

21. A reversible rotary engine comp rising a cylinder, pistons in the cylinder, a plurality of win s on each piston, a shaft passing loosely ,t rough the pistons, means for transmitting motion from the pistons to the shaft, other means for alternately locking the pistons against rotary movement, a plurality of ignition members located on two opposite sides respectively, of one of the iston wings when the latter is in locked position, the cylinder provided with inlet and exhaust ports located on two opposite sides of the remaining piston wing when in locked position, a valve controlling the inlet and exhaust ports, and means for simultaneously reversing the valve and energizing one or the other of the ignition members to reverse the direction of rotation of the shaft.

22. A rotary engine comprising a stationary cylinder, pistons turning in the cylinder, a rotatable shaft passing loosely through the pistons, \vingsfast on the pistons, transmission gears carried by the pistons and shaft, whereby motion is transmitted from the pistons to the shaft, the gears on the shaft interposed between the pistons and me hing with the gears on the respective pistons, and locking mechanism to alternately secure one of the pistons against movement in either direction, and to release the remaining piston.

.23. A reversible rotary engine comprising acylinder, pistons rotatable in the cylin er, wings on the pistons, releasable locking'means for temporarily retaining successive pistons against movement, the cylinder provided with inlet and exhaust ports, and a reversible valve controlling the admission of motive fluid to the cylinder through either port on one side or the other der, pistons mounted to rotate in the cylinder, a drive shaftt pa-ssing loosely through .ing position.

the cylinder, transmission gears carried by and directly connecting the pistons and shaft, and locking mechanism controlled by the pistons to releasably'and positively lock them successively against rotation in either direction.

25. A rotary engine comprising a cylinder, pistons in the cylinder, a shaft passing loosely through the pistons, intermcshing transmission gears carried by and directly connecting the pistons and shaft, and means other than the gearing for positively locking the pistons successively against rotation in either direction, such means arranged to partially release one piston to permit it to have a slight preliminary forward movement prior to its complete release, as the next adjacent piston approaches the lock- 26. A rotary engine comprising a cylinder, pistons therein, a shaft, means for transmitting motion from the pistons to the shaft, and means for locking the pistons alternately against movement, such means ineluding grooved drums carried by the pistons, movably supported locking means receivable in the grooves and automatically operating to prevent rotary movement of one or the other of the.drums, and means connecting the locking means of the respective drums to effect their alternate operation.

27. The combination, in a rotary gas engine, with a cylinder, pistons in the cylinder, wings on the respective pistons, and a shaft passing loosely through the pistons, of intermeshing transmission gears, the component parts of which are carried \by the pistons and the shaft respectively, and means for releasably and alternately locking the gear elements carried by the respective pistons against rotation.

28. A. reversible rotary engine comprising a cylinder, pistons rotatable in the cylinder, wings on the pistons, rel *asable locking means for temporarily retaining successive pistons against movement, the cylinder being provided with inlet and exhaust ports, andv means for controlling the admission of motive fluid to the cylinder through either port on one side or the other of a wing.

29. Ina 'rotary engine, the combination with a stationary cylinder, pistons rotating therein about their own axes, and capable of independent movement, and having wings, a drive shaft passing loosely through the pistons and journaled in the opposite ends of the cylinder, and means to introduce motive uid into the spaces between the pistons and to exhaust the proclucts of combustion, of transmission gearing connecting the pistons and the shaft, and looking members connected to each other and controlled by the rotation of the pistons to efi'ect the simultaneous locking and unlocking of the pistons alternately.

30. In a rotary engine, the combination with a cylinder having inlet and outlet ports leading toward a valve seat, pistons in the cylinder, and a drive shaft driven by the pistons, of a reversible valve in the seat .to control the admission of motive fluid to and the escape of'the spent gases from the cylinder, said valve comprising a shell having a port on the eriphery thereof to connect the inlet port of the cylinder with a source of supply led to the valve, and having a port extending axially therethrough communicating through an opening in the shell of the valve with the outlet port of the cylinder, to convey the spent gases from the cylinder and prevent their coigt-act with the valve seat.

31. In a rotary engine,.the combination with a cylinder having inlet and outlet ports leading toward a valve seat, pistons in the cylinder, and a drive shaft turned through the rotation of the pistons, of a reversible valve in the seat to control the admission of motive fluid to and the escape of the spent gases from the cylinder, said valve comprising a shell havin a peripheral port to admit the motive t uid to the. cyllnder inlet port, and an exhaust portseparated by the shell from the valve seat and communicating with the cylinder outlet port to provide for the escape of the spent gases and prevent their contact with the valve seat.

In a rotary engine, the combination with a cylinder, pistons in thecylinder, a

shaft passing loosely through the pistons,

and wings on the pistons, of transmission gearing on the pistons and shaft, for transmitting the rotary piston motion to the shaft,. and locking means independent of the gearing for positively and temporarily holding the successive piston wings and their pistons against rotation in either direction, and effective to prevent the contact of the piston wings with each other.

33. In a rotary engine, the combination with a cylinder, and pistons alternately rotatable therein, of a shaft passing loosely through the pistons, opposed driving gears on the pistons, driven gears secured to the shaft, and located between and meshing wit-h both driving gears, and effective both 'to transmit the motion of the alternately rotating pistons to the shaft, and to reduce the shaft speed while maintaining high power.

In testimony whereof, I aflix my signature in presence of two witnesses.

. FRANKLIN D. THOMAS.

Vl'itnesses RALPH S. lVARiuELn, RoY WALLIS. 

